1. Technical Field of the Invention
The present invention relates, generally, to a conveying apparatus.
More particularly, the present invention relates to a conveying apparatus having a fixed guide track and a guide track with a variable geometry. The variable guide track comprises several sections which are movable relative to the fixed guide track. The displacement of various sections of the variable guide track alters the distance between carriers arranged on a revolving chain in an area in which workpieces are transferred from a feed belt to a discharge belt.
In many areas of mass production, it is necessary to link machines with one another which carry out processing work on the articles to be manufactured. Both the processing speed and the distance between the products, that are consecutively being taken to the next processing station, may vary. Most processing machines require that the workpieces be supplied at regular (i.e., consistently equivalent) distances. These required distances may be smaller or greater than the distances between the arriving workpieces.
2. Description of the Prior Art
German Patent Document No. 195 10 649 discloses a conveying apparatus, in which a link chain is guided around three direction-changing wheels, of which one of the direction-changing wheels is supported in an elastically shiftable manner, for the purpose of tensioning the chain and compensating for differences in length. Between the two fixed direction-changing wheels, the chain is temporarily shortened by means of a zigzag-shaped pulling apart of the chain links. In the remaining regions (i.e., in the two strands between the fixed direction-changing wheels and the movable one), the chain runs in a tensioned condition (i.e., the pusher element links on every second articulated link of the chain.) In order to reduce the distance in the transfer region of the workpieces which are to be conveyed, the link axles between those that support the pusher elements are deflected from the curved track, which supports these link axles. The differing chain lengths which result from this deflection, and from the changes in the deflection, are absorbed by the third, elastically supported, direction-changing wheel.
In a further embodiment of the prior art apparatus, a deflection curve takes the place of the third, elastically supported direction-changing wheel; that deflecting curve is elastically adjustable and absorbs the changes in length.
The conveying apparatus of German Patent Document No. 195 10 649 fulfills the requirements imposed upon it, with regard to bringing the conveyed workpieces to a condition of equal distances. However, at high conveying velocities, this prior art installation tends to vibrate, a fact which causes loud noise and increased wear.
It is, therefore, an object of the present invention to provide a conveying apparatus, of the type having a link chain for processing work on articles in a manufacturing process, which will substantially reduce, if not eliminate, the disadvantages inherent in prior art conveying apparatus, such disadvantages including vibrations in the link chain in the region where the pusher elements are brought together.
The foregoing and related objects are achieved by the conveying apparatus of the present invention, which includes a fixed, closed-onto-itself guide track for a continuous conveyor chain with pusher elements, with the distances between the pusher elements along the fixed guide track being adjustable. The fixed guide track includes guided guide rollers on supporting axles for the pusher elements. A variably curved guide track guides intermediate axles with steering rollers and a drive wheel for driving the conveyor chain. The variable guide track further comprises a plurality of swingable, or shiftable, track sections and a first, fixed track section that envelops the drive wheel. The ends of the swingable, or shiftable, track sections are connected to each other and, via articulations, are connected with the stationary, or fixed, track section in an articulated manner via further articulations, with the entirety fixed, or stationary track section, along with the swingable, or shiftable, track sections, making up the closed, variable guide track.
By eliminating the non-driving, direction-changing wheels and by dividing the curved track (which guides the intermediate, non-pusher-carrying link axles) into a plurality of curved sections linked to one another in the articulated manner, the noise level of the conveying apparatus of the present invention is abated and the guidance of the link-chain axles, which carry the pushers, is simplified.